1. Field of the Invention
The present invention relates to evaluation of calibration precision.
2. Description of the Related Art
Printer calibration is carried out to compensate for the difference in color reproducibility between printer bodies. More specifically, calibration is carried out by adjusting an ink output characteristic so that reproduced colors of the machine to be calibrated are approximated to reproduced colors of the standard machine (see JP-A-2005-204053). In such case, patches of plural colors are printed, and an amount of shift of measured values of the patches from target reference values is grasped. The ink output characteristic is corrected so that the shift amount is compensated for. Such calibration can conform the reproduced colors of the machine to be calibrated to the reproduced colors of the standard machine. However, when calibration has not been carried out properly, there is a possibility that an amount of color shift may be produced between the reproduced colors of the machine to be calibrated and the reproduced colors of the standard machine. Due to this, patches for precision confirmation are printed by the machine which has been calibrated so that measured color values are evaluated, whereby calibration precision is evaluated.
However, calibration precision cannot properly be grasped unless printing/color measuring conditions for the patches used in the calibration correspond with printing/color measuring conditions for the patches used to confirm calibration precision. More specifically, when both printing/color measuring conditions differ from each other, evaluation of calibration precision reflects color shifts resulting from the differences of the printing/color measuring conditions. As a result, true evaluation of calibration precision cannot be carried out. For example, print sheet of the patches used in the calibration differs from print sheet of the patches to confirm calibration precision, a measured color value of each patch reflects the differences of background-colors of the print sheets, whereupon it is difficult to carry out true evaluation of calibration precision. It is obviously desirable to completely conform the printing/color measuring conditions for the patches used in the calibration to the printing/color measuring conditions for the patches used to confirm calibration precision. However, it is difficult to familiarize users with the complete correspondence.